Abstract:
Transparent conductors combine two generally contradictory physical properties, but there
are numerous applications where both functionalities are crucial. Previous searches focused
on doping wide-gap metal oxides. Focusing instead on the family of 18 valence electron
ternary ABX compounds that consist of elements A, B and X in 1:1:1 stoichiometry, we search
theoretically for electronic structures that simultaneously lead to optical transparency while
accommodating intrinsic defect structures that produce uncompensated free holes. This
leads to the prediction of a stable, never before synthesized TaIrGe compound made of
all-metal heavy atom compound. Laboratory synthesis then found it to be stable in the
predicted crystal structure and p-type transparent conductor with a strong optical absorption
peak at 3.36 eV and remarkably high hole mobility of 2,730 cm2V - 1 s - 1 at room temperature.
This methodology opens the way to future searches of transparent conductors in
unexpected chemical groups.
